Switching devices having a movable contact member for producing an isolating distance, and having a switching element integrated in the contact member are known as fuse disconnecting switches. In these devices, the movable contact members contain fuses whose ends are provided with blade contacts, as is described in, for example, German Utility Model G 94 04 155.5.
It is also conventional for a load-current switch or circuit-breaker to be connected toward the input side in series with a switching unit, for example a soft starter for three-phase asynchronous motors.
For electronic branch switches, the use of semiconductor switching elements which, for example, contain silicon or, in a particularly advantageous way, silicon carbide as substrate is recommended. Despite the outstanding insulating properties of silicon carbide given appropriate driving into the locking state, a visible isolating distance is to be ensured for safety reasons in the case of interruption of the current flow.